1. : a metal or metallic alloy used when melted to join metallic surfaces and usually applied by means of a soldering iron or a blowpipe with a flux (as rosin, borax, or zinc chloride) to cleanse the surfaces ; especially : an alloy of lead and tin so used

2. : something (as a shared principle) that serves to unite or cement : a common bond

II. verb

( soldered ; soldered ; soldering -d(ə)riŋ ; solders )

transitive verb

1. : to unite or make whole by means of solder

solder a joint in piping

solder a leaky pot

solder up a hole

solder sheets of metal together

2. : to bring into or restore to firm union as if by the use of solder : cause to adhere, knit, close up, or come together as if soldered

a friendship soldered by common interests

— often used with up

the union was soldered up by concessions from both sides

intransitive verb

1. : to use solder : make unions or repairs by means of solder

was soldering away at a free form when I got there

workmen who like to solder

2. obsolete : to constitute a source of union

3. : to become united or repaired by or as if by solder

the joint solders easily

Webster's New International English Dictionary.Новый международный словарь английского языка Webster.2012